Honestly I don't quite get the argument of "too many poly's would crash the game". I can already make my game fall to it's knees by planting trees everywhere, where's the limitations to how many seeds I can plant in a single chunk ? I can make my base be a nightmare to navigate through by enabling shadows and putting too many lights everywhere, how is the game supposed to lock me out of doing that ?
People can always wreck their game in various ways, I find it quite sad that we're unable to make use of all the awesome decorations the artists make, because of something taken to the extreme by a handful of players. A new tool (special wrench or whatever) to be found in the world that lets you pickup various deco blocks for you to take away would be such an amazing thing to do besides opening cupboards and sinks.